I switched to titanium needles from Superior (I suppose there are other brands, also). I never have problems with dull needles or burrs. So, I change them when they break-usually because I hit a pin dead on or hit the throat plate because I have not been careful as I set up different feet for different stitch patterns. I have a large selection of needle types and sizes and use the appropriate one for the project I am working on. I store needles I am using in a red tomato pin cushion that I have written needle information in the various sections. I use a flower pin in the section from which I took the needle in the machine-that way I know what is there. I have been amazed at how long needles last. I see no need to throw away a needle that is causing no difficulty because I have used it for a pre-determined time.